Decreased sleep efficiency, increased wake after sleep onset and increased cortical arousals in late pregnancy

Validation of a sleep-disordered breathing screening questionnaire during pregnancy and comparison between mothers and bedpartners prediction of risk

BACKGROUND

Sleep Disorder Breathing (SDB) in pregnant patients ranges from 3 to 27% and varies depending on gestational age and method used to diagnose. SDB increases the risk of advanced pregnancy complications such as gestational diabetes mellitus, pregnancy-induced hypertension, and preeclampsia. Screening and diagnosis of SDB during pregnancy remains a challenge, with existing screening tools underperforming during pregnancy. This study aimed to validate a previously developed model for predicting SDB during late pregnancy and compare the predictive value of bedpartner responses.

METHODS

Ninety-six women in the third trimester of pregnancy underwent polysomnography and completed the Berlin Questionnaire (BQ), with 81 bedpartners completing the BQ about their pregnant partner. A subset of BQ items (snoring volume and tiredness upon awakening) along with BMI > 32 kg/m2 was utilised to calculate the Wilson Optimized Model (WOM), which demonstrated strong predictive properties in development.

RESULTS

SDB (RDI/hr ≥ 5) was detected in 43.8% of women. BQ identified 72% of pregnant mothers as high risk for SDB (Sensitivity = 83%, Specificity = 37%), compared to 29% of mothers identified by the WOM (Sensitivity = 45%, Specificity = 83%). At RDI of ≥ 15, the WOM correctly classified more women according to SDB risk than the BQ (76.0% vs. 41.7% cases correct, X2(1) = 23.42, p < .001), with no difference at RDI ≥ 5. Bedpartners were more likely to report high risk for SDB on the WOM than pregnant women themselves (38.3% vs. 28.4%), however predictive ability was not improved by bedpartner input (RDI ≥ 5 bedpartner AUC = 0.69 v mother AUC = 0.73).

CONCLUSION

BQ largely overestimates the prevalence of SDB in pregnancy compared to the WOM which underestimates. Utilising bedpartner responses didn't improve screening for SDB in late pregnancy. More work is needed to develop a pregnancy-specific tool for quick and accurate screening for SDB.

Sleep conditions and sleep hygiene behaviors in early pregnancy are associated with gestational diabetes mellitus: A propensity-score matched study

PURPOSE

To explore the influence of sleep conditions and sleep hygiene behaviors in early pregnancy on gestational diabetes mellitus (GDM) development.

METHODS

This 1:1 propensity-score matched study included 1,216 pregnant women divided into GDM and control groups based on diagnosis via the oral glucose tolerance test at 24-28 gestational weeks. Sleep conditions and hygiene behaviors were evaluated using structural questionnaires, including the Pittsburgh Sleep Quality Index, Epworth Sleepiness Scale, and Sleep Hygiene Practice Scale. Univariate and multivariate logistic regression analyses and Spearman's correlation were conducted to identify the associations.

RESULTS

After adjusting for baseline clinical characteristics, women with GDM were more likely to have poor sleep quality (adjusted odds ratio [AOR] = 1.585, 95% confidence interval [CI]: 1.261-1.992) and higher scores for subjective sleep quality, latency, duration, efficiency, and sleep disturbances (all P < 0.01). Mild sleepiness (AOR = 1.311, 95% CI: 1.012-1.699) and worrying about not being able to fall asleep (AOR = 1.123, 95% CI: 1.005-1.255) were more likely to occur in the GDM group. Sleep quality and hygiene behaviors such as sleep-irrelevant activities, staying in bed after waking up, weekend catch-up sleep, and overeating before bedtime were significantly correlated with gestational diabetes variables.

CONCLUSION

Poor sleep conditions and specific sleep hygiene behaviors in early pregnancy may be independent risk factors for GDM. This suggests that sleep assessment and behavior education can be used as new approaches for the early implementation of surveillance and prevention of GDM.

Effects of sleep quality in early pregnancy on pregnancy outcomes and mood state

PURPOSE

To clarify the relationship between quality of sleep and pregnancy outcomes and to explore how sleep quality affects mood state in the first trimester of pregnancy.

METHODS

This prospective cohort study enrolled pregnant women from June 2020 to June 2021. Maternal sleep conditions, daytime sleepiness, and mood state in the first trimester were assessed using four Chinese self-rating scales, namely, the Pittsburgh Sleep Quality Index (PSQI), the Sleep Hygiene Practice Scale (SHPS), Epworth Sleepiness Scale (ESS), and the abbreviated version of the Profile of Mood States (a-POMS). Participants were divided into an exposed group (PSQI score > 5, poor sleep quality group) and a non-exposed group (PSQI score ≤ 5, good sleep quality group). Maternal characteristics, pregnancy outcomes, and the relationship among sleep quality, sleepiness, and mood state were analyzed. Comparisons of sleep hygiene behavior variables between the two subgroups were also analyzed.

RESULTS

A total of 2703 pregnant women were enrolled in the study. Poor sleep quality increased the probability of gestational diabetes mellitus (GDM) (1.573, 1.315-1.863), liver function damage (1.467, 1.021-2.107), preterm delivery (1.468, 1.077-2.002), mild sleepiness (1.612, 1.357-1.915), and excessive sleepiness (2.134, 1.686-2.701). Poor maternal sleep quality was significantly associated with the occurrence of preterm premature rupture of membranes (1.947, 1.168-3.243) and perinatal death (1.003, 1.000-1.006). Additionally, a significant positive correlation between the PSQI score and the total mood disturbance (TMD) score was revealed by Spearman's correlation analysis (r = 0.378, P < 0.01). Enter Regression analysis demonstrated that sleep quality (R2 = 0.390, P < 0.01) and sleepiness (R2 = 0.234, P < 0.01) exerted significant direct effects on mood state during pregnancy. Furthermore, Spearman's correlation analysis indicated a positive association between the PSQI score and the SHPS total score (r = 0.227, P < 0.01).

CONCLUSIONS

Poor sleep quality is significantly associated with elevated rates of maternal mood disturbances, obstetric complications, and adverse outcomes in infants. The findings suggest that it may be useful to provide comprehensive sleep assessment and education on sleep hygiene during the early stages of pregnancy.

Impact of maternal posture on fetal physiology in human pregnancy: a narrative review

In numerous medical conditions, including pregnancy, gravity and posture interact to impact physiology and pathophysiology. Recent investigations, for example, pertaining to maternal sleeping posture during the third trimester and possible impact on fetal growth and stillbirth risk highlight the importance and potential clinical implications of the subject. In this review, we provide an extensive discussion of the impact of maternal posture on fetal physiology from conception to the postpartum period in human pregnancy. We conducted a systematic literature search of the MEDLINE database and identified 242 studies from 1991 through 2021, inclusive, that met our inclusion criteria. Herein, we provide a synthesis of the resulting literature. In the first section of the review, we group the results by the impact of maternal posture at rest on the cervix, uterus, placenta, umbilical cord, amniotic fluid, and fetus. In the second section of the review, we address the impact on fetal-related outcomes of maternal posture during various maternal activities (e.g., sleep, work, exercise), medical procedures (e.g., fertility, imaging, surgery), and labor and birth. We present the published literature, highlight gaps and discrepancies, and suggest future research opportunities and clinical practice changes. In sum, we anticipate that this review will shed light on the impact of maternal posture on fetal physiology in a manner that lends utility to researchers and clinicians who are working to improve maternal, fetal, and child health.

An enriched environment ameliorates maternal sleep deprivation-induced cognitive impairment in aged mice by improving mitochondrial function via the Sirt1/PGC-1α pathway

BACKGROUND

Early life stress can cause cognitive impairment in aged offspring. Environmental enrichment (EE) is considered to be an effective non-pharmacological treatment for improving cognitive decline. The aim of this research was to evaluate the effect of EE, on cognitive impairment in aged offspring induced by maternal sleep deprivation (MSD) and the underlying mechanisms involved to investigate its potential value in clinical practice.

METHODS

CD-1 damns were subjected or not to sleep deprivation during late gestation. Twenty-one days after birth, the offspring were assigned to standard or EE cages. At 18 months-old, the learning and memory function of the offspring mice was evaluated using Morris water maze. The hippocampal and prefrontal cortical levels of protein, gene, proinflammation cytokines, and oxidative stress indicators was examined by Western blot, real-time polymerase chain reaction, enzyme linked immunosorbent assay, and biochemical assays.

RESULTS

Offspring in MSD group exhibited declined learning and memory abilities compared with control animals. Moreover, the hippocampal and prefrontal cortical levels of Sirtuin1 (Sirt1), peroxisome proliferator-activated receptor-gamma coactivator-1 alpha (PGC-1α), postsynaptic density protein-95, and synaptophysin were lower and those of proinflammation cytokines higher in the MSD group; meanwhile, the superoxide dismutase content was higher and the malondialdehyde and reactive oxygen species contents were lower. However, these deleterious changes were ameliorated by exposure to EE.

CONCLUSIONS

EE attenuates MSD-induced cognitive impairment, oxidative stress, and neuroinflammation and reverses the reduction in synaptic protein levels in aged offspring mice via the Sirt1/PGC-1α pathway.

Maternal cardiorespiratory coupling: differences between pregnant and nonpregnant women are further amplified by sleep-stage stratification

Pregnancy complications are associated with abnormal maternal autonomic regulation. Subsequently, thoroughly understanding maternal autonomic regulation during healthy pregnancy may enable the earlier detection of complications, in turn allowing for the improved management thereof. Under healthy autonomic regulation, reciprocal interactions occur between the cardiac and respiratory systems, i.e., cardiorespiratory coupling (CRC). Here, we investigate, for the first time, the differences in CRC between healthy pregnant and nonpregnant women. We apply two algorithms, namely, synchrograms and bivariate phase-rectified signal averaging, to nighttime recordings of ECG and respiratory signals. We find that CRC is present in both groups. Significantly less (P < 0.01) cardiorespiratory synchronization occurs in pregnant women (11% vs. 15% in nonpregnant women). Moreover, there is a smaller response in the heart rate of pregnant women corresponding to respiratory inhalations and exhalations. In addition, we stratified these analyses by sleep stages. As each sleep stage is governed by different autonomic states, this stratification not only amplified some of the differences between groups but also brought out differences that remained hidden when analyzing the full-night recordings. Most notably, the known positive relationship between CRC and deep sleep is less prominent in pregnant women than in their nonpregnant counterparts. The decrease in CRC during healthy pregnancy may be attributable to decreased maternal parasympathetic activity, anatomical changes to the maternal respiratory system, and the increased physiological stress accompanying pregnancy. This work offers novel insight into the physiology of healthy pregnancy and forms part of the base knowledge needed to detect abnormalities in pregnancy.NEW & NOTEWORTHY We compare CRC, i.e., the reciprocal interaction between the cardiac and respiratory systems, between healthy pregnant and nonpregnant women for the first time. Although CRC is present in both groups, CRC is reduced during healthy pregnancy; there is less synchronization between maternal cardiac and respiratory activity and a smaller response in maternal heart rate to respiratory inhalations and exhalations. Stratifying this analysis by sleep stages reveals that differences are most prominent during deep sleep.

Vision-based detection and quantification of maternal sleeping position in the third trimester of pregnancy in the home setting-Building the dataset and model

In 2021, the National Guideline Alliance for the Royal College of Obstetricians and Gynaecologists reviewed the body of evidence, including two meta-analyses, implicating supine sleeping position as a risk factor for growth restriction and stillbirth. While they concluded that pregnant people should be advised to avoid going to sleep on their back after 28 weeks' gestation, their main critique of the evidence was that, to date, all studies were retrospective and sleeping position was not objectively measured. As such, the Alliance noted that it would not be possible to prospectively study the associations between sleeping position and adverse pregnancy outcomes. Our aim was to demonstrate the feasibility of building a vision-based model for automated and accurate detection and quantification of sleeping position throughout the third trimester-a model with the eventual goal to be developed further and used by researchers as a tool to enable them to either confirm or disprove the aforementioned associations. We completed a Canada-wide, cross-sectional study in 24 participants in the third trimester. Infrared videos of eleven simulated sleeping positions unique to pregnancy and a sitting position both with and without bed sheets covering the body were prospectively collected. We extracted 152,618 images from 48 videos, semi-randomly down-sampled and annotated 5,970 of them, and fed them into a deep learning algorithm, which trained and validated six models via six-fold cross-validation. The performance of the models was evaluated using an unseen testing set. The models detected the twelve positions, with and without bed sheets covering the body, achieving an average precision of 0.72 and 0.83, respectively, and an average recall ("sensitivity") of 0.67 and 0.76, respectively. For the supine class with and without bed sheets covering the body, the models achieved an average precision of 0.61 and 0.75, respectively, and an average recall of 0.74 and 0.81, respectively.

Sex hormone dose escalation for treating abnormal sleep in ovariectomized rats: in vitro GABA synthesis in sleep-related brain areas

No data in the literature have evaluated sex hormone dose escalation for treating abnormal sleep of ovariectomized rats-nor studies on the role of sex hormones in GABA synthesis of rats' sleep-related areas. The main aim of this study was to determine the maximum tolerated dose (MTD) of estradiol (ET), progesterone (PT), and the mixture of both (EPT) to restore normal sleep in a model of menopause in rats. The second purpose was to describe the in vitro activity of glutamate decarboxylase (GAD) in sleep-related brain areas in the presence or absence of sex hormones. A weekly dose-escalation design of ET, PT, or EPT was implemented in ovariectomized rats (six per group). Dose escalation continued until the dose at which 100% of the rats exhibited a state of "complete somnolence." Doses that were not toxic or did not show side effects were considered. For in vitro experiments, sleep-related brain areas were separated and incubated with radiolabeled glutamate. Estradiol (17β-E2), progesterone (P), and pyridoxal phosphate (PLP) were added to this assay, and GAD activity was determined. Under the same conditions, a second test was carried out, but the P antagonist RU486 was added to assess the role of P in GAD activity. Ovariectomy increased periodic awakenings compared to those determined for the SHAM group. The EPT for ovariectomized rats was very effective by the fifth week in decreasing arousal and achieving a similar sleep behavior to the SHAM-control group. Rats tolerated the ET, PT, and EPT well to the maximum planned dose (0.66 mg/kg and 4.4 mg/kg, respectively). No lethal events occurred; the MTD was reached. The in vitro studies indicated that the presence of 17β-E2 plus P in the assay triggered the activity of isotype 65 GAD in all the studied brain areas. RU486 in the incubation medium blocked such activity; however, the action of isotype 67 GAD was not blocked by RU486. A dose-escalation model was determined; the MTD coincided with the maximum dose of ET and PT used. However, the EPT combination restored normal sleep in the menopause model compared to the SHAMs without toxic effects. The in vitro model demonstrated that 17β-E2 plus P presence in the assay increased the activity of GAD65 in the studied brain tissues.

Common sleep disorders in pregnancy: a review

In this review, we provide a comprehensive overview of common sleep disorders during pregnancy, including their characterization, prevalence, risk factors, and possible contribution to maternal and fetal outcomes. We conducted a quasi-systematic literature search of the MEDLINE database and identified 744 studies from 1991 through 2021, inclusive, that met our inclusion criteria. We synthesized the existing literature on sleep disorders during pregnancy and highlighted controversies, research gaps, and needed clinical developments. Our review covers a range of sleep disorders, including insomnia, obstructive sleep apnea, restless legs syndrome, and circadian rhythm disorders. We discuss the prevalence of these disorders in pregnancy and their potential impact on maternal and fetal health outcomes. We also explore the relationship between sleep disorders, pre-pregnancy comorbidities such as obesity, and pregnancy-related conditions such as gestational diabetes mellitus and preeclampsia. In addition to summarizing the existing literature on sleep disorders during pregnancy, we also highlight opportunities for further research in this area. We suggest that future studies should strive to employ validated and objective measurement tools for sleep disorders and prioritize utilization of longitudinal methods with participant follow-up through postpartum, mid-life, menopause, and beyond. We also put forward investigation into the impact of circadian rhythm disruption on reproductive physiology and early pregnancy outcomes as an area of important work. Overall, our review provides valuable insights on sleep and reproduction and into common sleep disorders during pregnancy and their potential impact on maternal and fetal health outcomes.

Comprehensive evaluation of machine learning algorithms for predicting sleep-wake conditions and differentiating between the wake conditions before and after sleep during pregnancy based on heart rate variability

Introduction

Perinatal women tend to have difficulties with sleep along with autonomic characteristics. This study aimed to identify a machine learning algorithm capable of achieving high accuracy in predicting sleep-wake conditions and differentiating between the wake conditions before and after sleep during pregnancy based on heart rate variability (HRV).

Methods

Nine HRV indicators (features) and sleep-wake conditions of 154 pregnant women were measured for 1 week, from the 23rd to the 32nd weeks of pregnancy. Ten machine learning and three deep learning methods were applied to predict three types of sleep-wake conditions (wake, shallow sleep, and deep sleep). In addition, the prediction of four conditions, in which the wake conditions before and after sleep were differentiated-shallow sleep, deep sleep, and the two types of wake conditions-was also tested.

Results and Discussion

In the test for predicting three types of sleep-wake conditions, most of the algorithms, except for Naïve Bayes, showed higher areas under the curve (AUCs; 0.82-0.88) and accuracy (0.78-0.81). The test using four types of sleep-wake conditions with differentiation between the wake conditions before and after sleep also resulted in successful prediction by the gated recurrent unit with the highest AUC (0.86) and accuracy (0.79). Among the nine features, seven made major contributions to predicting sleep-wake conditions. Among the seven features, "the number of interval differences of successive RR intervals greater than 50 ms (NN50)" and "the proportion dividing NN50 by the total number of RR intervals (pNN50)" were useful to predict sleep-wake conditions unique to pregnancy. These findings suggest alterations in the vagal tone system specific to pregnancy.

An enriched environment improves maternal sleep deprivation-induced cognitive deficits and synaptic plasticity via hippocampal histone acetylation

INTRODUCTION

Growing evidence clearly demonstrates that maternal rodents exposure to sleep deprivation (SD) during late pregnancy impairs learning and memory in their offspring. Epigenetic mechanisms, particularly histone acetylation, are known to be involved in synaptic plasticity, learning, and memory. We hypothesize that the cognitive decline induced by SD during late pregnancy is associated with histone acetylation dysfunction, and this effect could be reversed by an enriched environment (EE).

METHODS

In the present study, pregnant CD-1 mice were exposed to SD during the third trimester of pregnancy. After weaning, all offspring were randomly assigned to two subgroups in either a standard environment or an EE. When offspring were 3 months old, the Morris water maze was used to evaluate hippocampal-dependent learning and memory ability. Molecular biological techniques, including western blot and real-time fluorescence quantitative polymerase chain reaction, were used to examine the histone acetylation pathway and synaptic plasticity markers in the hippocampus of offspring.

RESULTS

The results showed that the following were all reversed by EE treatment: maternal SD (MSD)-induced cognitive deficits including spatial learning and memory; histone acetylation dysfunction including increased histone deacetylase 2 (HDAC2) and decreased histone acetyltransferase (CBP), and the acetylation levels of H3K9 and H4K12; synaptic plasticity dysfunction including decreased brain-derived neurotrophic factor; and postsynaptic density protein-95.

CONCLUSIONS

Our findings suggested that MSD could damage learning ability and memory in offspring via the histone acetylation pathway. This effect could be reversed by EE treatment.

The Insomnia Severity Index: Factor Structure and Measurement and Structural Invariance across Perinatal Time Points

Insomnia is associated with adverse outcomes in women in the perinatal period; thus, the assessment of insomnia is important for pregnant women. The Insomnia Severity Index (ISI) is an instrument used globally to assess the severity of insomnia. However, its factor structure and structural invariance for pregnant women have not been studied. Therefore, we aimed to conduct factor analyses to search for the best model to fit its structural invariance. A cross-sectional study with the ISI was conducted at one hospital and five clinics in Japan from January 2017 to May 2019. A set of questionnaires was administered on two occasions with a one-week interval. The study included 382 pregnant women ranging in gestational age from 10 to 13 weeks. One week later, 129 participants answered the retest. After exploratory and confirmatory factor analyses, the measurement and structural invariance between parity and two time points was tested. The two-factor structure model showed an acceptable fit for the ISI in pregnant women (χ² (12) = 28.516, CFI = 0.971, RMSEA = 0.089). The model also showed satisfactory measurement and structure invariance between parity and time points. The findings indicate that the ISI's use would be appropriate for pregnant women as a two-factor subscale of "severity" and "impact", regardless of the parity or time point. The ISI's factor structure may vary by subject; hence, it is necessary to confirm the measurement and structural invariance of the subject for whom the ISI will be used. Furthermore, interventions that focus not only on total scores and cutoff points but also on the phenomenon of subscales should be considered.

SmartMoms Canada: An evaluation of a mobile app intervention to support a healthy pregnancy

BACKGROUND

There is a lack of cost-effective and readily available access to evidence-based information to manage healthy behaviours for pregnant individuals. Mobile health (mHealth) tools offer a cost-effective, interactive, personalized option that can be delivered anywhere at a time most convenient for the user. This study protocol was primarily developed to, i) assess the feasibility of the SmartMoms Canada intervention in supporting participants to achieve gestational weight gain (GWG) guidelines. The secondary objectives are to, ii) assess user experience with the app, measured by adherence to the program via app software metrics and frequency of use, iii) determine the impact of SmartMoms Canada app usage on the adoption of healthful behaviours related to nutrition, physical activity and sleep habits, improvements in health-related quality of life, pregnancy-related complications, and symptoms of depression, and iv) investigate the potential extended effects of the app on postpartum health-related outcomes.

METHODS

This is a feasibility trial. Pregnant individuals aged 18-40 years with pre-gravid body mass index between 18.5 and 39.9 kg/m², carrying a singleton fetus, having Wi-Fi access, and at ≤20 weeks' gestation will be recruited. Eligible people will be followed from recruitment until 12 months postpartum.

DISCUSSION

SmartMoms Canada is the first bilingual Canadian-centric app designed for pregnant people. This mHealth intervention, with its ability to supply frequent interactions, provides pregnancy- related health knowledge to users, potentially leading to an improvement in pregnancy-related outcomes and behaviours, and, ultimately a reduction in the present economic burden related to in-person interventions.

TRIAL REGISTRATION

ISRCTN, ISRCTN16254958. Registered 20 December 2019, http://www.isrctn.com/ ISRCTN16254958.

Altered cognition and anxiety in adolescent offspring whose mothers underwent different-pattern maternal sleep deprivation, and cognition link to hippocampal expressions of Bdnf and Syt-1

Background

Inadequate sleep during pregnancy negatively affects the neural development of offspring. Previous studies have focused on the continuous sleep deprivation (CSD) paradigm, but the sleep pattern during late pregnancy is usually fragmented.

Objective

To compare the effects of CSD and fragmented sleep deprivation (FSD) in late pregnancy on emotion, cognition, and expression of synaptic plasticity-related proteins in offspring mice.

Methods

Pregnant CD-1 mice were either subjected to 3/6 h of CSD/FSD during gestation days 15-21, while those in the control group were left untreated. After delivery, the offspring were divided into five groups, i.e., control (CON), short or long CSD (CSD3h, CSD6h), and short or long FSD (FSD3h, FSD6h). When the offspring were 2 months old, the anxiety-like behavior level was tested using the open field (OF) and elevated plus maze (EPM) test, and spatial learning and memory were evaluated using the Morris water maze (MWM) test. The expression of hippocampal of brain-derived neurotrophic factor (Bdnf) and synaptotagmin-1 (Syt-1) was determined using RT-PCR and western blotting.

Results

The CSD6h, FSD3h, and FSD6h had longer latency, fewer center times in the OF test, less open arms time and fewer numbers of entries in the open arms of the EPM, longer learning distance swam and lower memory percentage of distance swam in the target quadrant in the MWM test, and decreased BDNF and increased Syt-1 mRNA and protein levels in the hippocampus. Compared to the CSD6h, the FSD3h and FSD6h had longer distance swam, a lower percentage of distance swam in the target quadrant, decreased BDNF, and increased Syt-1 mRNA and protein levels in the hippocampus.

Conclusion

The results suggested that maternal sleep deprivation during late pregnancy impairs emotion and cognition in offspring, and FSD worsened the cognitive performance to a higher extent than CSD. The observed cognitive impairment could be associated with the expression of altered hippocampal of Bdnf and Syt-1 genes.

The short-term effect of a mHealth intervention on gestational weight gain and health behaviors: The SmartMoms Canada pilot study

Gestational weight gain (GWG) has been shown to impact several maternal-infant outcomes. Since healthcare provider guidance on weight gain and healthy behaviors alone has failed to help women to meet guidelines during pregnancy, a practical adjunctive approach is to deliver evidence-based behavior change programs through mobile interventions. The present study aimed to assess the short-term effect of the SmartMoms Canada app to promote adequate GWG and healthy behaviors. Twenty-nine pregnant women were recruited in this app-based intervention trial to test whether a higher app usage (≥ 3.8 min·week^-1) between 12-20 gestational weeks and 24-28 gestational weeks improved GWG, diet, physical activity, and sleep, compared to women with a lower app usage (< 3.8 min·week^-1). Two-way mixed ANOVA for repeated measures was used to estimate the effect of the app usage and time, as well as their interaction on GWG and healthy behaviors. The likelihood ratio was used to examine the association between app usage categorization and GWG classification. Cramer's V statistic was used to estimate the effect size for interpretation of the association. Pregnant women using the SmartMoms Canada app more frequently had a higher moderate-to-vigorous physical activity (MVPA) daily average when compared with women with a lower usage (mean difference: 17.84 min/day, 95% CI: 2.44; 33.25). A moderate effect size (28.6% vs. 15.4%; Cramer's V = 0.212) was found for the association between app categorization and rate of GWG, representing a greater adherence to the GWG guidelines in women in the higher app usage group vs. the lower app usage group. Considering other physical activity, diet, and sleep variables, no app categorization effect was observed. A short-term higher usage of SmartMoms Canada app has a positive effect on objectively-measured MVPA.

Cognitive Function Decline in the Third Trimester of Pregnancy Is Associated with Sleep Fragmentation

During late pregnancy, sleep deterioration is regularly observed. In concert with these observations, in previous studies by other researchers, a slight objective cognitive decline in pregnant women has been found. Sleep is essential for memory consolidation. The hypothesis of the study was that cognitive impairment could be related to sleep deterioration during pregnancy. The study included 19 pregnant women in their third trimester of pregnancy (28−40 weeks, median 33 weeks (IQR 32−37)) recruited at the Department of Gynecology and Obstetrics, Medical University of Warsaw, and 20 non-pregnant women as controls. The assessment was performed using the vocabulary subtest from the Wechsler Adult Intelligence Scale (WAIS), D2 Test of Attention, OSPAN task (Operational Span Task) to assess cognitive performance, actigraphy to examine sleep parameters, and a set of self-report instruments: Athens Insomnia Scale (AIS), Beck Depression Inventory (BDI), Ford Insomnia Response to Stress (FIRST), Regenstein Hyperarousal Scale (HS), and Epworth Sleepiness Scale (ESS). Although there were no differences between the groups in WAIS (p = 0.18), pregnant women had worse scores in working memory capacity (overall number of remembered letters: p = 0.012, WM span index: p = 0.004) and a significantly lower score in attention (p = 0.03). Pregnant women also had lower sleep efficiency (p = 0.001), more awakenings from sleep (p = 0.001), longer average awakenings (p < 0.0001), longer wake after sleep onset (WASO, p < 0.0001), and longer total time in bed (p < 0.0001). In psychological assessment, pregnant women had only a higher FIRST score (p = 0.02). Using mediation analysis, we found that frequent awakening might be the major factor contributing to deterioration in working memory performance, explaining almost 40% of the total effect. In conclusion, sleep fragmentation in the third trimester of pregnancy may impair working memory consolidation. Pregnant women often complain about poor daily performance as well as non-restorative sleep. In this study, we showed that there is a relationship between lower sleep quality in pregnancy and worse cognitive functioning. We can expect a cognitive decline in women with sleep disturbances in pregnancy. Therefore, we should pay more attention to the treatment of sleep disorders in pregnancy.

Sex Hormones, Sleep, and Memory: Interrelationships Across the Adult Female Lifespan

As the population of older adults grows, so will the prevalence of aging-related conditions, including memory impairments and sleep disturbances, both of which are more common among women. Compared to older men, older women are up to twice as likely to experience sleep disturbances and are at a higher risk of cognitive decline and Alzheimer's disease and related dementias (ADRD). These sex differences may be attributed in part to fluctuations in levels of female sex hormones (i.e., estrogen and progesterone) that occur across the adult female lifespan. Though women tend to experience the most significant sleep and memory problems during the peri-menopausal period, changes in memory and sleep have also been observed across the menstrual cycle and during pregnancy. Here, we review current knowledge on the interrelationships among female sex hormones, sleep, and memory across the female lifespan, propose possible mediating and moderating mechanisms linking these variables and describe implications for ADRD risk in later life.

Environmental Enrichment Reverses Maternal Sleep Deprivation-Induced Anxiety-Like Behavior and Cognitive Impairment in CD-1 Mice

Preclinical studies have clearly indicated that offspring of mothers who suffered sleep deprivation during pregnancy exhibit anxiety, depression-like behaviors, and cognitive deficits. The cognitive impairment induced by maternal sleep deprivation (MSD) is currently poorly treated. Growing evidence indicates that an enriched environment (EE) improves cognition function in models of Alzheimer’s disease, schizophrenia, and lipopolysaccharide. However, the effects of EE on hippocampal-dependent learning and memory, as well as synaptic plasticity markers changes induced by MSD, are unclear. In the present study, pregnant CD-1 mice were randomly divided into a control group, MSD group, and MSD+EE group. Two different living environments, including standard environment and EE, were prepared. When male and female offspring were 2 months, the open field test and elevated plus maze were used to assess anxiety-like behavior, and the Morris water maze was used to evaluate hippocampal learning and memory. Western blotting and real-time fluorescence quantitative polymerase chain reaction were used to detect the expression of brain-derived neurotrophic factor and Synaptotagmin-1 in the hippocampus of offspring. The results revealed that MSD-induced offspring showed anxiety-like behaviors and cognitive impairment, while EE alleviated anxiety-like behavior and cognitive impairment in offspring of the MSD+EE group. The cognitive impairment induced by MSD was associated with a decreased brain-derived neurotrophic factor and an increased Synaptotagmin-1, while EE increased and decreased brain-derived neurotrophic factor and Synaptotagmin-1 in the hippocampus of mice from the MSD+EE group, respectively. Taken together, we can conclude that EE has beneficial effects on MSD-induced synaptic plasticity markers changes and can alleviate anxiety-like behaviors and cognitive impairment.

Association Between Objectively Assessed Sleep and Depressive Symptoms During Pregnancy and Post-partum

Introduction

Sleep problems are common in pregnancy but many studies have relied only on self-reported sleep measures. We studied the association between objectively measured sleep and peripartum depressive symptoms in pregnant women.

Material and Methods

Sleep was assessed using Actiwatch accelerometers in a sample of 163 pregnant women in the late first (weeks 11–15) or early second trimester (weeks 16–19). Depressive symptoms were assessed in gestational weeks 17, 32 and at 6 weeks post-partum using the Edinburgh Postnatal Depression Scale (EPDS). Multiple linear regression and logistic regression analyses, adjusting for age, BMI, pre-pregnancy smoking, ongoing mental health problems, trimester and season of sleep assessment were carried out to test the association between sleep and depression. Sleep was measured by total sleep time and sleep efficiency, whereas depression was indicated by depressive symptoms and depression caseness. Results are presented as unstandardized beta (B) coefficients or adjusted odds ratios (AOR) and 95% confidence intervals (CI).

Results

Total sleep time ranged from 3 to 9 h (mean 7.1, SD 0.9) and average sleep efficiency was 83% (SD 6.0). Women with the shortest total sleep time, i.e., in the lowest quartile (<6.66 h), reported higher depressive symptoms during pregnancy (week 17, B = 2.13, 95% CI 0.30–3.96; week 32, B = 1.70, 95% CI 0.03–3.37) but not post-partum. Their probability to screen positive for depression in gestational week 17 was increased more than 3-fold (AOR = 3.46, 95% CI 1.07–11.51) but unchanged with regards to gestational week 32 or 6 weeks post-partum. Sleep efficiency was not associated with depressive symptoms at any stage of pregnancy or post-partum.

Discussion

In one of the few studies to use objective sleep measures to date, mental health of pregnant women appeared to be affected by shortened sleep, with total sleep time being negatively associated with depressive symptoms in the early second and third trimester. This finding highlights the relevance of identifying and treating sleep impairments in pregnant women early during antenatal care to reduce the risk of concomitant depression.

A Technology-Based Pregnancy Health and Wellness Intervention (Two Happy Hearts): Case Study

BACKGROUND

The physical and emotional well-being of women is critical for healthy pregnancy and birth outcomes. The Two Happy Hearts intervention is a personalized mind-body program coached by community health workers that includes monitoring and reflecting on personal health, as well as practicing stress management strategies such as mindful breathing and movement.

OBJECTIVE

The aims of this study are to (1) test the daily use of a wearable device to objectively measure physical and emotional well-being along with subjective assessments during pregnancy, and (2) explore the user's engagement with the Two Happy Hearts intervention prototype, as well as understand their experiences with various intervention components.

METHODS

A case study with a mixed design was used. We recruited a 29-year-old woman at 33 weeks of gestation with a singleton pregnancy. She had no medical complications or physical restrictions, and she was enrolled in the Medi-Cal public health insurance plan. The participant engaged in the Two Happy Hearts intervention prototype from her third trimester until delivery. The Oura smart ring was used to continuously monitor objective physical and emotional states, such as resting heart rate, resting heart rate variability, sleep, and physical activity. In addition, the participant self-reported her physical and emotional health using the Two Happy Hearts mobile app-based 24-hour recall surveys (sleep quality and level of physical activity) and ecological momentary assessment (positive and negative emotions), as well as the Perceived Stress Scale, Center for Epidemiologic Studies Depression Scale, and State-Trait Anxiety Inventory. Engagement with the Two Happy Hearts intervention was recorded via both the smart ring and phone app, and user experiences were collected via Research Electronic Data Capture satisfaction surveys. Objective data from the Oura ring and subjective data on physical and emotional health were described. Regression plots and Pearson correlations between the objective and subjective data were presented, and content analysis was performed for the qualitative data.

RESULTS

Decreased resting heart rate was significantly correlated with increased heart rate variability (r=-0.92, P<.001). We found significant associations between self-reported responses and Oura ring measures: (1) positive emotions and heart rate variability (r=0.54, P<.001), (2) sleep quality and sleep score (r=0.52, P<.001), and (3) physical activity and step count (r=0.77, P<.001). In addition, deep sleep appeared to increase as light and rapid eye movement sleep decreased. The psychological measures of stress, depression, and anxiety appeared to decrease from baseline to post intervention. Furthermore, the participant had a high completion rate of the components of the Two Happy Hearts intervention prototype and shared several positive experiences, such as an increased self-efficacy and a normal delivery.

CONCLUSIONS

The Two Happy Hearts intervention prototype shows promise for potential use by underserved pregnant women.

Comparison of longitudinal diary and actigraphy-assessed sleep in pregnant women

STUDY OBJECTIVES

Various methods are employed to assess sleep in pregnant women, including self-report, sleep diary, and actigraphy. Unfortunately, the data are often contradictory, and interpretations are often inconsistent. The current aims are to compare subjective and objective sleep data in pregnant women collected longitudinally in early pregnancy.

METHODS

In this secondary analysis of 104 pregnant women, sleep was collected via diary and actigraphy for 14 days during three separate occasions (10-12 weeks; 14-16 weeks; and 18-20 weeks). Sleep variables included wake after sleep onset (WASO), sleep efficiency (SE), bedtime/lights out, sleep onset latency (SL), and total sleep duration (TST). Repeated measures ANOVAs compared each sleep variable across Time and by Method of data collection, while controlling for parity and daytime naps.

RESULTS

Significant differences were noted for only the method of data collection for sleep component studied for WASO, F (1, 98) = 147.20, p < 0.001; SE, F (1, 98) = 129.41, p < 0.001); bedtime/lights out, F (1, 103) = 5.33, p < 0.05); and sleep duration, F (1, 104) = 182.75, p < 0.001). Significant variation was not seen in any variable across time-period.

CONCLUSIONS

There are substantial discrepancies between diary- and actigraphy-assessed sleep measures in pregnant women which is in alignment with previous literature. These data highlight that these methodologies assess different constructs. We contend that these data may be useful as a reference to compare high-risk women or those with sleep disorders. Using a multi-modal approach to identify sleep disturbance in pregnancy is likely a more clinically useful option.

The Significance and Limitations of Monitoring Sleep during Pregnancy

Sleep patterns often change during pregnancy and postpartum. However, if severe and persistent, these changes can depict a risk factor for significant health complications. It is thus essential to identify and understand changes in women's sleeping pattern over the course of pregnancy and postpartum, to offer an appropriate and timely intervention if necessary. In this paper, we discuss sleep disturbances during pregnancy and their association with pregnancy complications. We also review the state-of-the-art digital devices for real-time sleep assessment, and highlight their strengths and limitations.Clinical Relevance-This review highlights an importance of an individualized holistic pregnancy care program which engages both the healthcare professionals and the obstetric population, together with an educational module to increase the user awareness on the importance of sleep disturbances and their consequences during and after pregnancy.

Sleep and physical activity from before conception to the end of pregnancy in healthy women: a longitudinal actigraphy study

BACKGROUND

Sleep and physical activity changes are common in pregnancy, but longitudinal data starting before conception are scarce. Our aim was to determine the changes of the daily total sleep time (TST) and physical activity duration (PAD) from before conception to end of pregnancies in respect of pregestational maternal factors.

METHODS

This longitudinal observational study formed part of the CONIMPREG research project and recruited healthy women planning to become pregnant. Sleep and physical activity were recorded around-the-clock for ≥4 days via actigraphy before conception and during each trimester of pregnancy. Data were adjusted according to pregestational maternal body composition, parity and age.

RESULTS

Among 123 women with eligible data, the unadjusted mean (95% confidence interval) TST increased from 415.3 min (405.5-425.2 min) before conception to 458.0 min (445.4-470.6 min) in the 1st trimester, remaining high through the 2nd and 3rd trimesters. Variation was substantial before conception (±2SD range: 307-523 min). The unadjusted mean PAD before conception was 363.7 min (±2SD range: 120-608 min), decreasing sharply to 262.1 min in the first trimester and more gradually thereafter. Vigorous and moderate activity decreased more than light activity. TST and PAD were significantly associated with age, parity, and pregestational body fat percentage; lean body mass was negatively correlated with TST. Results were generally unaffected by seasonal variations.

CONCLUSION

Marked variations were found in pregestational TST and PAD. Healthy women slept ≥30 min longer during pregnancy, while PAD decreased by ≥ 90 min in early pregnancy and continued to decrease thereafter.

Sleep, evening light exposure and perceived stress in healthy nulliparous women in the third trimester of pregnancy

Objective

Sleep disturbances are common in pregnancy, and the prevalence increases during the third trimester. The aim of the present study was to assess sleep patterns, sleep behavior and prevalence of insomnia in pregnant women in the third trimester, by comparing them to a group of non-pregnant women. Further, how perceived stress and evening light exposure were linked to sleep characteristics among the pregnant women were examined.

Methods

A total of 61 healthy nulliparous pregnant women in beginning of the third trimester (recruited from 2017 to 2019), and 69 non-pregnant women (recruited in 2018) were included. Sleep was monitored by actigraphy, sleep diaries and the Bergen Insomnia Scale. The stress scales used were the Relationship Satisfaction Scale, the Perceived Stress Scale and the Pre-Sleep Arousal Scale. Total white light exposure three hours prior to bedtime were also assessed.

Results

The prevalence of insomnia among the pregnant women was 38%, with a mean score on the Bergen Insomnia Scale of 11.2 (SD = 7.5). The corresponding figures in the comparing group was 51% and 12.3 (SD = 7.7). The pregnant women reported lower sleep efficiency (mean difference 3.8; 95% CI = 0.3, 7.3), longer total sleep time derived from actigraphy (mean difference 59.0 minutes; 95% CI = 23.8, 94.2) and higher exposure to evening light (mean difference 0.7; 95% CI = 0.3, 1.2), compared to the non-pregnant group. The evening light exposure was inversely associated with total sleep time derived from actigraphy (B = -8.1; 95% CI = -14.7, -1.5), and an earlier midpoint of sleep (B = -10.3, 95% CI = -14.7, -5.9). Perceived stressors were unrelated to self-reported and actigraphy assessed sleep.

Conclusion

In healthy pregnant participants sleep in the third trimester was preserved quite well. Even so, the data suggest that evening light exposure was related to shorter sleep duration among pregnant women.

Fetal heart rate during maternal sleep

Despite prolonged and cumulative exposure during gestation, little is known about the fetal response to maternal sleep. Eighty-four pregnant women with obesity (based on pre-pregnancy BMI) participated in laboratory-based polysomnography (PSG) with continuous fetal electrocardiogram monitoring at 36 weeks gestation. Multilevel modeling revealed both correspondence and lack of it in maternal and fetal heart rate patterns. Fetal heart rate (fHR) and variability (fHRV), and maternal heart rate (mHR) and variability (mHRV), all declined during the night, with steeper rates of decline prior to 01:00. fHR declined upon maternal sleep onset but was not otherwise associated with maternal sleep stage; fHRV differed during maternal REM and NREM. There was frequent maternal waking after sleep onset (WASO) and fHRV and mHRV were elevated during these episodes. Cross-correlation analyses revealed little temporal coupling between maternal and fetal heart rate, except during WASO, suggesting that any observed associations in maternal and fetal heart rates during sleep are the result of other physiological processes. Implications of the maternal sleep context for the developing fetus are discussed, including the potential consequences of the typical sleep fragmentation that accompanies pregnancy.

A systematic literature review and meta-analysis of the clinical effects of aroma inhalation therapy on sleep problems

BACKGROUND

This systematic review investigated the clinical effects of inhalation aromatherapy for the treatment of sleep problems such as insomnia.

METHODS

Studies on sleep problems and inhalation aromatherapy, published in Korean and international journals, were included in the meta-analysis. Five domestic and international databases, respectively each, were used for the literature search. Keywords included sleep disorder, sleep problems, insomnia, and aroma inhalation, and the related literature was further searched. After the screening, selected articles were assessed for their quality and conducted the risk of bias using RevMan 5.0, a systematic literature review was then conducted. A meta-analysis comparing the averages was conducted on studies that reported numerical values. Additionally, meta-analysis of variance and meta-regression analyses were performed.

RESULTS

Meta-analysis of the 34 studies using the random-effects model revealed that the use of aromatherapy was highly effective in improving sleep problems such as insomnia, including quantitative and qualitative sleep effects (95% confidence interval [CI], effect sizes = 0.6491). Subgroup analysis revealed that the secondary outcomes including stress, depression, anxiety, and fatigue were significantly effective. The single aroma inhalation method was more effective than the mixed aroma inhalation method. Among the single inhalation methods, the lavender inhalation effect was the greatest.

CONCLUSION

Inhalation aromatherapy is effective in improving sleep problems such as insomnia. Therefore, it is essential to develop specific guidelines for the efficient inhalation of aromatherapy.

ETHICS AND DISSEMINATION

Ethical approval is not required because individual patient data are not included. The findings of this systematic review were disseminated through peer-reviewed publications or conference presentations.

PROSPERO REGISTRATION NUMBER

CRD42020142120.

A Review of Sleep Architecture and Sleep Changes During Pregnancy

Importance

Poor sleep is widely recognized as a common complaint in pregnancy, and yet there are incomplete data on the exact nature of these complaints, what their implications for fetal and maternal health are, and how to best recognize and address these significant health issues.

Objectives

The purpose of this article is to review the current literature on the changes in objectively measured sleep parameters that occur during pregnancy, identify any possible trends, and discuss current implications for obstetric outcomes and treatments.

Evidence Acquisition

PubMed NCBI and Google Scholars database were searched for a variety of sleep-related terms, and articles were selected based on relevance to the topic and method of sleep pattern monitoring.

Results

Poor sleep is ubiquitous during pregnancy, and the relatively few studies evaluating the issue using objective polysomnography have small sample sizes. However, data suggests sleep architecture changes begin as early as the first trimester, and there is evidence that primigravid sleep structure never returns to prepregnancy levels after birth. In addition, cesarean delivery frequency, early labor, labor length, depression, gestational hypertension, and gestational diabetes all appear to be influenced by sleep changes. Current treatments are based on nonpregnant populations and may not be appropriate for the gravid patient.

Conclusions and Relevance

Disordered sleep is a more widespread and serious issue than most women are aware, and there are numerous obstetric and general health implications to cause clinician concern. More research is needed on both electroencephalography architecture changes and treatment options.

Insomnia symptoms during pregnancy: A meta-analysis

Reports of sleep disturbances are common during pregnancy, yet estimates of prevalence of insomnia symptoms during pregnancy vary widely. The goals of the current review were to summarize the existing data on prevalence of insomnia symptoms during pregnancy and to explore potential moderators, including trimester, gestational age, maternal age, symptoms of anxiety and symptoms of depression. A systematic search of PubMed, PsycInfo and Web of Science was conducted for articles published from inception up to June 2020. In total, 24 studies with a total of 15,564 participants were included in the analysis. The overall prevalence of insomnia symptoms during pregnancy was 38.2%. Trimester was a significant moderator, such that prevalence of insomnia symptoms was higher in the third trimester (39.7%) compared to first (25.3%) and second (27.2%) trimesters. No other variables significantly moderated the prevalence of insomnia symptoms. The results of the current meta-analysis suggest that the prevalence of insomnia symptoms is higher during pregnancy, particularly in the third trimester. Future research should examine the efficacy and safety of insomnia treatments with this population.

Pregnant women do not display impaired memory formation across one night of sleep

Forgetfulness is a common complaint of pregnant women, who also often report impaired nocturnal sleep. Considering sleep's well-known beneficial role in consolidating newly encoded memory content, we hypothesized that pregnant women would display detrimental changes in objective sleep measures and associated memory deficits. We compared the consolidation of declarative as well as procedural memory across sleep in 21 healthy, third-trimester pregnant women versus 20 matched non-pregnant controls. Subjects encoded and were tested on visuospatial and procedural memory tasks before and after, respectively, a night of sleep spent at home. The emergence of gist-based memories was tested with the Deese-Roediger-McDermott (DRM) paradigm. Sleep was polysomnographically recorded and subjective sleep quality was assessed with questionnaires. Although pregnant in comparison to non-pregnant women reported markedly impaired subjective sleep quality and efficiency, quantitative changes were limited to increases in wakefulness after sleep onset and reductions in rapid eye movement (REM) sleep. Retention of newly learned memory contents, which is believed to reflect sleep-associated memory consolidation, was comparable between groups, as was the formation of gist-based memories. The findings indicate that subjective deteriorations in sleep quality experienced by pregnant women are not necessarily linked to objective impairments. They raise the possibility that sufficient slow wave sleep towards the end of pregnancy allows for normal sleep-related memory consolidation. Although these results were obtained in a small number of pregnant women in very good health and should be corroborated in larger samples, they challenge the assumption of poor sleep and impaired memory as hallmarks of the "pregnancy brain".

Continuous 7-Month Internet of Things-Based Monitoring of Health Parameters of Pregnant and Postpartum Women: Prospective Observational Feasibility Study

BACKGROUND

Monitoring during pregnancy is vital to ensure the mother's and infant's health. Remote continuous monitoring provides health care professionals with significant opportunities to observe health-related parameters in their patients and to detect any pathological signs at an early stage of pregnancy, and may thus partially replace traditional appointments.

OBJECTIVE

This study aimed to evaluate the feasibility of continuously monitoring the health parameters (physical activity, sleep, and heart rate) of nulliparous women throughout pregnancy and until 1 month postpartum, with a smart wristband and an Internet of Things (IoT)-based monitoring system.

METHODS

This prospective observational feasibility study used a convenience sample of 20 nulliparous women from the Hospital District of Southwest Finland. Continuous monitoring of physical activity/step counts, sleep, and heart rate was performed with a smart wristband for 24 hours a day, 7 days a week over 7 months (6 months during pregnancy and 1 month postpartum). The smart wristband was connected to a cloud server. The total number of possible monitoring days during pregnancy weeks 13 to 42 was 203 days and 28 days in the postpartum period.

RESULTS

Valid physical activity data were available for a median of 144 (range 13-188) days (75% of possible monitoring days), and valid sleep data were available for a median of 137 (range 0-184) days (72% of possible monitoring days) per participant during pregnancy. During the postpartum period, a median of 15 (range 0-25) days (54% of possible monitoring days) of valid physical activity data and 16 (range 0-27) days (57% of possible monitoring days) of valid sleep data were available. Physical activity decreased from the second trimester to the third trimester by a mean of 1793 (95% CI 1039-2548) steps per day (P<.001). The decrease continued by a mean of 1339 (95% CI 474-2205) steps to the postpartum period (P=.004). Sleep during pregnancy also decreased from the second trimester to the third trimester by a mean of 20 minutes (95% CI -0.7 to 42 minutes; P=.06) and sleep time shortened an additional 1 hour (95% CI 39 minutes to 1.5 hours) after delivery (P<.001). The mean resting heart rate increased toward the third trimester and returned to the early pregnancy level during the postpartum period.

CONCLUSIONS

The smart wristband with IoT technology was a feasible system for collecting representative data on continuous variables of health parameters during pregnancy. Continuous monitoring provides real-time information between scheduled appointments and thus may help target and tailor pregnancy follow-up.

Relationships between objective sleep parameters and inflammatory biomarkers in pregnancy

We examined the relationships between sleep and inflammatory biomarkers during late pregnancy. Seventy-four women underwent an overnight sleep assessment by polysomnography. Blood samples were collected before bedtime and again within 1 h upon awakening to measure C-reactive protein (CRP), interleukin (IL)-6, and IL-6 soluble receptor. Sleep parameters included variables characterizing sleep architecture and sleep continuity. The participants were 32.2 (SD = 4.1) years old, and the average gestational age was 32.8 (3.5) weeks. Controlling for covariates, evening CRP was negatively associated with N3 sleep (β = -0.30, P = 0.010). N3 sleep was also negatively associated with morning CRP (β = -0.26, P = 0.036), with a higher percentage of N3 sleep associated with a lower level of morning CRP. Contrarily, there was a tendency for a positive association between stage N2 sleep and morning CRP (β = 0.23, P = 0.065). Stage N1 sleep was associated with morning IL-6 (β = 0.28, P = 0.021), with a higher percentage of N1 sleep associated with a higher morning IL-6. No significant associations were found between morning inflammatory biomarkers and sleep continuity parameters. In conclusion, increased light sleep was associated with increased inflammatory biomarkers, whereas more deep sleep was associated with decreased inflammatory biomarkers. These findings further support the interactions between sleep and the immune system during late pregnancy.

Pulse transit time in pregnancy: a new way to diagnose and classify sleep disordered breathing?

STUDY OBJECTIVES

There are significant discrepancies between the prevalence of snoring and that of objectively defined sleep disordered breathing among pregnant women, suggesting subtle airflow limitations that may not be captured by conventional scoring. This study examined the performance of pulse transit time, an indirect measure of arterial stiffness and sympathetic activation, in pregnancy.

METHODS

Pregnant women with obesity and snoring and a group of controls without symptoms of sleep disordered breathing were recruited in the first trimester. Women underwent a level III in-laboratory sleep monitoring study including an electrocardiogram and pulse oximetry, and pulse transit time was measured. Sleep disordered breathing was defined as an apnea-hypopnea index at least five events per hour of sleep. Statistical analysis was performed using Spearman correlation, Fisher's exact t-test, and univariate analysis.

RESULTS

Of the 222 women, 38 met criteria for sleep disordered breathing. Pulse transit time drops were very prevalent (95% of participants with snoring had > 5 drops per hour). Median apnea-hypopnea index was 0.7 (interquartile range [IQR]: 2.6) events per hour whereas median pulse transit time drop index was 20.70 (IQR: 35.90) events per hour. Pulse transit time index was significantly higher in snorers with apnea-hypopnea index less than five events per hours and participants with apnea-hypopnea index greater than five events per hour compared to controls. Examination of random epochs with pulse transit time drops showed that 95% of pulse transit time drops were associated with airflow limitation.

CONCLUSIONS

Pulse transit time ascertains frequent events of sympathetic activation in at-risk women with and without sleep disordered breathing beyond conventional apneas and hypopneas. Pulse transit time may be an important addition to the identification of clinically significant sleep disordered breathing in pregnant women, and may identify more sleep disordered breathing than apnea-hypopnea index.

Insomnia symptoms increase during pregnancy, but no increase in sleepiness - Associations with symptoms of depression and anxiety

OBJECTIVE

To evaluate alteration in insomnia and sleepiness symptoms during pregnancy and assess early pregnancy risk factors for these symptoms, especially depressive and anxiety symptoms.

METHODS

A cohort of 1858 women was enrolled from the FinnBrain Birth Cohort Study. Insomnia and sleepiness symptoms were measured in early, mid- and late pregnancy with the Basic Nordic Sleep Questionnaire. Depressive symptoms were measured using the Edinburgh Postnatal Depression Scale and anxiety symptoms with the Symptom Checklist-90/Anxiety Scale. General linear models for repeated measures were conducted.

RESULTS

General sleep quality decreased (p < 0.001) and all insomnia types (p < 0.001) and sleep latencies (p < 0.001) increased as pregnancy proceeded. Snoring increased, but witnessed apneas remained rare. Nevertheless, morning (p = 0.019) and daytime (p < 0.001) sleepiness decreased from early to both mid-pregnancy and late pregnancy (p = 0.006 and p = 0.039). Women took more naps in early and late pregnancy compared to mid-pregnancy (both p < 0.001). Women with higher baseline anxiety symptoms had greater increase in sleep latency. At each pregnancy point, higher depressive and anxiety symptoms were associated with higher insomnia (p < 0.001) and sleepiness scores (p < 0.001) and higher depressive symptoms with longer sleep latencies (p < 0.001).

CONCLUSION

We found a marked increase in insomnia symptoms throughout pregnancy. However, sleepiness symptoms did not increase correspondingly. Both depressive and anxiety symptoms in early pregnancy were associated with higher insomnia and sleepiness symptoms in later stages of pregnancy which emphasizes the importance of their assessment in early pregnancy.

Associations between symptoms of sleep-disordered breathing and maternal sleep patterns with late stillbirth: Findings from an individual participant data meta-analysis

BACKGROUND AND OBJECTIVES

Sleep-disordered breathing (SDB) affects up to one third of women during late pregnancy and is associated with adverse pregnancy outcomes, including hypertension, diabetes, impaired fetal growth, and preterm birth. However, it is unclear if SDB is associated with late stillbirth (≥28 weeks' gestation). The aim of this study was to investigate the relationship between self-reported symptoms of SDB and late stillbirth.

METHODS

Data were obtained from five case-control studies (cases 851, controls 2257) from New Zealand (2 studies), Australia, the United Kingdom, and an international study. This was a secondary analysis of an individual participant data meta-analysis that investigated maternal going-to-sleep position and late stillbirth, with a one-stage approach stratified by study and site. Inclusion criteria: singleton, non-anomalous pregnancy, ≥28 weeks' gestation. Sleep data ('any' snoring, habitual snoring ≥3 nights per week, the Berlin Questionnaire [BQ], sleep quality, sleep duration, restless sleep, daytime sleepiness, and daytime naps) were collected by self-report for the month before stillbirth. Multivariable analysis adjusted for known major risk factors for stillbirth, including maternal age, body mass index (BMI kg/m2), ethnicity, parity, education, marital status, pre-existing hypertension and diabetes, smoking, recreational drug use, baby birthweight centile, fetal movement, supine going-to-sleep position, getting up to use the toilet, measures of SDB and maternal sleep patterns significant in univariable analysis (habitual snoring, the BQ, sleep duration, restless sleep, and daytime naps). Registration number: PROSPERO, CRD42017047703.

RESULTS

In the last month, a positive BQ (adjusted odds ratio [aOR] 1.44, 95% confidence interval [CI] 1.02-2.04), sleep duration >9 hours (aOR 1.82, 95% CI 1.14-2.90), daily daytime naps (aOR 1.52, 95% CI 1.02-2.28) and restless sleep greater than average (aOR 0.62, 95% CI 0.44-0.88) were independently related to the odds of late stillbirth. 'Any' snoring, habitual snoring, sleep quality, daytime sleepiness, and a positive BQ excluding the BMI criterion, were not associated.

CONCLUSION

A positive BQ, long sleep duration >9 hours, and daily daytime naps last month were associated with increased odds of late stillbirth, while sleep that is more restless than average was associated with reduced odds. Pregnant women may be reassured that the commonly reported restless sleep of late pregnancy may be physiological and associated with a reduced risk of late stillbirth.

Characteristics of sleep/wake problems and delivery outcomes among pregnant Japanese women without gestational complications

Background

Frequently observed sleep/wake problems among pregnant women need comprehensive evaluation. This study was conducted to clarify the sleep/wake problems among pregnant women without gestational complications during the second and third trimester and the effects of sleep/wake problems on delivery outcomes.

Methods

A total of 88 Japanese pregnant women participated in this study. In their second and third trimester, subjective sleep quality, insomnia severity, excessive daytime sleepiness (EDS), and restless legs syndrome/Willis-Ekbom disease (RLS/WED) were assessed using questionnaires; also, sleep disordered breathing (SDB) was screened using a pulse oximeter.

Results

From the second to the third trimester, an increasing tendency of sleep/wake problems was observed. During the third trimester, the percentages of women experiencing decreased subjective sleep quality, difficulty maintaining sleep (DMS), EDS, RLS/WED, and 3% oxygen desaturation index (ODI) values ≥5/h were 62.5, 45.5, 48.9, 9.1, and 29.5%, respectively. In a logistic regression analysis for EDS in the third trimester, the adjusted odds ratio (95% confidence interval) of total sleep duration < 6 h, moderate to severe DMS, and 3% ODI values ≥5/h were 3.25 (1.16–9.10), 4.74 (1.60–14.00), and 0.90 (0.28–2.89), respectively. Although short sleep durations, decreased subjective sleep quality, EDS, and SDB did not affect delivery outcomes or the infant’s condition, the percentage of women undergoing cesarean sections in the severe insomnia group was significantly higher (p = 0.008).

Conclusions

Sleep/wake problems were frequent during pregnancy, especially during the third trimester. EDS among pregnant women was associated with shorter sleep durations and DMS rather than SDB. The effect of factors related to insomnia on delivery outcomes should thus be considered a crucial problem among pregnant Japanese women without gestational complications in clinical practice.

Sleep complaints in early pregnancy. A cross-sectional study among women attending prenatal care in general practice

BACKGROUND

Sleep problems in late pregnancy are common, but sleep in early pregnancy is less well described. The aim of this study was to describe the occurrence and severity of sleep complaints in early pregnancy. We asked the women about worries due to sleep problems. Furthermore, we investigated the associations between sleep complaints and pregnancy-related symptoms. This association was studied taking into account physical and mental health, sociodemographic characteristics, and reproductive history of the women.

METHODS

Cross-sectional study in Danish general practice based on an electronic questionnaire completed by pregnant women and a Pregnancy Health Record filled in by the general practitioner (GP). The questionnaire measured three sleep complaints and 11 common physical pregnancy-related symptoms. The sleep complaints were measured as mild, moderate or severe, and it was recorded how much they worried the women. The associations between the physical pregnancy-related symptoms and sleep complaints were assessed by odds ratios from multivariable logistic regression models.

RESULTS

The questionnaire was completed by 1338 out of 1508 eligible women before the end of gestation week 16. The gestational age ranged from 5 to 16 weeks (median 11 weeks) among the included women. On average, more than one third of the women reported to have at least one of the three sleep complaints in the questionnaire. Problems "taking a long time to fall asleep" was reported by 312 women (23%), "waking up too early" was reported by 629 (47%), and 183 (14%) had been "lying awake most of the night". One sleep complaint was reported by 38%, two by 16, and 4% had all three symptoms. The majority were not at all or only mildly worried because of their sleep disturbances, but moderate or severe worries were found among 46% of those" taking a long time to fall asleep" and among 40% of those "lying awake most of the night". "Moderate or severe complaints" were reported by 277 (21%) women "Moderate or severe complaints" were associated with pregnancy-related physical symptoms, such as back pain, pelvic girdle pain and pelvic cavity pain, but only the association with pelvic cavity pain stayed significant after adjustment for depression.

CONCLUSION

This study showed that sleep complaints in early pregnancy are common, and sleep complaints showed association with physical as well as mental symptoms. It may be important for pregnant patients that clinicians address depression, and mood in relation to sleep problems during pregnancy.

Prevalence and associated risk factors of insomnia among pregnant women in China

BACKGROUND

Insomnia is common during pregnancy but the prevalence and risk factors of insomnia in Chinese women during pregnancy is not well studied. This study aimed to examine the prevalence of insomnia and its risk factors in Chinese women during pregnancy.

METHODS

In this cross sectional study, 436 Chinese pregnant women with Insomnia Severity Index (ISI) ≥ 8 were clinically assessed using the insomnia criteria based on the combination of DSM-IV (Diagnostic and Statistical Manual-4th Edition) and ICD-10 (International Classification of Dieases, 10th Edition). Beck Depression Inventory (BDI), State-Trait Anxiety Inventory (STAI), Dysfunctional Beliefs and Attitudes about Sleep Scale (DBAS), Pregnancy Pressure Scale (PPS), Perceived physical discomfort level and number, Epworth Sleepiness Scale (ESS), and a general socio-demographic questionnaire were administered.

RESULTS

The results showed that about 20% of the pregnant women met the strict diagnosis criteria of insomnia. Independent-samples t-test revealed that several risk factors were correlated with the group with insomnia (N = 84) compared to the group without insomnia (N = 352). Binary Logistic regression analysis found that more significant bed partner influence (OR = 1.92, 95% CI: 1.03-3.60), depressive symptoms (OR = 1.07, 95% CI: 1.00-1.14), daytime sleepiness (OR = 1.07, 95% CI: 1.01-1.14), subjective somatic discomfort (OR = 2.27, 95% CI: 1.11-4.65), kinds of somatic discomfort (OR = 1.14, 95% CI: 1.03-1.27) and later gestation (OR = 1.05, 95% CI: 1.01-1.09) were significantly associated with insomnia.

CONCLUSION

In this cohort of Chinese pregnant women, about a fifth of women suffered from clinically significant insomnia. Measures to prevent the adverse effects of insomnia should be provided to pregnant women with depressive symptoms, Sleep disturbance of the bed partner, excessive daytime sleepiness and somatic discomfort, especially late in gestation.

Antenatal sleep quality associated with perinatal outcomes in women of advanced maternal age

OBJECTIVES

The increasing prevalence of advanced maternal age (AMA) coupled with poor sleep quality among pregnant women makes it important to study their association with perinatal outcomes. However, little is known about the interaction of AMA and maternal antenatal sleep on perinatal outcomes. Here, we examined whether associations between AMA and perinatal outcomes are modified by antenatal sleep quality.

PARTICIPANTS

Data were collected from 446 women, with a singleton pregnancy and no pregnancy complications, who participated in the Growing Up in Singapore Towards healthy Outcomes (GUSTO) birth cohort study.

MEASUREMENTS

Participants completed the Pittsburgh Sleep Quality Index (PSQI) at 26-28 weeks gestation and had perinatal outcome data collected upon delivery. Interactions between AMA and maternal sleep quality on perinatal outcomes were investigated and where significant, analyses were further stratified by maternal age. All analyses were adjusted for maternal BMI at 26-28 weeks gestation, ethnicity, and maternal education.

RESULTS

Neonates of mothers of AMA and poor sleep quality (PSQI score >5) had increased odds of stay in the neonatal intensive care unit (adjusted odds ratio = 3.53, 95% CI: -1.21 to 10.27) and shorter birth length (adjusted mean difference = -1.05 cm, 95% CI: -1.82 to -0.20), as compared with women of AMA and good sleep quality (PSQI score ≤5). In women <35 years, sleep quality did not associate with perinatal outcomes.

CONCLUSION

Poor sleep quality in women of AMA was associated with neonatal health outcomes. Improving maternal antenatal sleep may potentially improve perinatal outcomes in offspring of women of AMA.

Polysomnographic features of pregnancy: A systematic review

Symptoms of sleep disturbances are common among pregnant women and generally worsen across gestation. Pregnancy-related sleep disorders are not only associated with a poor quality of life of the affected mothers, but also with adverse perinatal outcomes, including perinatal depression, gestational diabetes, preeclampsia, and preterm birth. The current knowledge about the impact of sleep disorders during pregnancy largely derives from the results of sleep surveys conducted in various populations. However, the number of studies examining changes in objective sleep variables during pregnancy via polysomnography has progressively increased in recent years. Here we systematically reviewed the polysomnographic studies available in the literature with the aim to describe the sleep pattern and to identify possible markers of sleep disruption in pregnant women. Based on our analysis, subjective worsening of sleep quality across gestation is related to objective changes in sleep macrostructure, which become particularly evident in the third trimester. Pregnancy per se does not represent an independent risk factor for developing major polysomnography-assessed sleep disorders in otherwise healthy women. However, in women presenting predisposing factors, such as obesity or hypertension, physiological changes occurring during pregnancy may contribute to the onset of pathological conditions, especially sleep-disordered breathing, which must be carefully considered.

Sleep in Pregnancy and Maternal Hyperglycemia: a Narrative Review

PURPOSE OF REVIEW

Prevalence of gestational diabetes is increasing globally and sleep may be a modifiable lifestyle factor associated with it. However, existing findings have been inconsistent.

RECENT FINDINGS

Majority of studies reviewed found a link between extreme sleep durations and elevated risk of maternal hyperglycemia. The findings with sleep-disordered breathing are less consistent. Methodological differences across studies, in terms of sleep assessment methods (subjective vs. objective), study population (low vs. high risk), classification of gestational diabetes and sleep problems, may have contributed to the inconsistent findings. Some studies also suggest the possibility of trimester-specific association between sleep and maternal hyperglycemia. Large-scale prospective studies comprising objective measurements of sleep, preferably over three trimesters and preconception, are needed to better evaluate the relationship between sleep and maternal hyperglycemia.

Sleep Disturbances and Modulations in Inflammation: Implications for Pregnancy Health

When a woman becomes pregnant, there is a vast series of physiological, vascular, and psychological changes. Among the most commonly reported changes are those involving sleep. Pregnant women report that their ability to maintain sleep and acquire continuous refreshing sleep is impaired during the perinatal period as compared to the non-pregnant period. A growing literature supports the hypothesis that disturbed sleep (which comes in many forms) during the perinatal period is associated with an increased risk of adverse maternal, delivery, and infant outcomes. Among the suggested biological pathways linking sleep and adverse outcomes are disturbances in the immune and hormonal systems. The following paper will discuss (1) the various sleep processes that are commonly disturbed during the perinatal period and the methods used to collect sleep data; (2) the evidence linking sleep to adverse outcomes; and (3) how one specific biological pathway, the immune system, likely mediates these associations. The goal of this paper is to clarify the role that sleep disturbance has during pregnancy.

Obstructive sleep apnoea in multiple pregnancy

Obstructive sleep apnoea (OSA) during pregnancy has been associated with gestational diabetes mellitus, hypertension and low birth weight. Multiple pregnancy is associated with similar adverse perinatal outcomes. Multiple pregnancy rates have risen with increased access to assisted conception; simultaneously, advancing maternal age and weight are also driving a rise in the incidence of OSA in pregnancy. The intersection of OSA and multiple pregnancy would be presumed to have significant maternal and fetal morbidity; however, specific data are sparse. We review the current state of knowledge on OSA in multiple pregnancy.

Clinical effects of mindfulness meditation and cognitive behavioral therapy standardized for insomnia: A protocol for a systematic review and meta-analysis

INTRODUCTION

This systematic review protocol describes the methods that will be used to evaluate the efficacy and safety of mindfulness meditation and cognitive behavioral therapy programs as a psychological intervention for insomnia disorders.

METHODS AND ANALYSIS

We will search the following 11 electronic databases without language or publication status restrictions: MEDLINE, the Cochrane Central Register of Controlled Trials, EMBASE, Allied and Complementary Medicine Database, Cumulative Index to Nursing and Allied Health Literature, and PsycARTICLES. Furthermore, we will also search 5 Korean-language databases (Oriental Medicine Advanced Searching Integrated System, Korean studies Information Service System, Research Information Service System, Korean Medical Database, and Korea Citation Index). The study selection and data extraction will be performed independently by 2 authors. The study quality assessment and evaluation of the quality of evidence for the main findings will be performed independently by 2 authors using the Cochrane tool for assessing risk of bias and predefined criteria (the Grading of Recommendations Assessment, Development, and Evaluation approach). Data synthesis and analysis will be performed using RevMan Version 5.3. Data will be synthesized by either a fixed effects or random effects model according to a heterogeneity test or the number of studies included in the meta-analysis. If any plan for documenting important protocol amendments changes, the researchers will have a revision agreement and then register the modification in the International Prospective Register of Systematic Reviews (PROSPERO).

ETHICS AND DISSEMINATION

Ethical approval will not be required because individual patient data are not included and because this protocol is for a systematic review. The findings of this systematic review will be disseminated through conference presentations.PROSPERO registration number: CRD42018111217.

Obstructive sleep apnea as a risk factor for preeclampsia-eclampsia

PURPOSE

Preeclampsia-eclampsia remains one of the leading causes of maternal and perinatal morbidity and mortality. Emerging evidence suggests that obstructive sleep apnea (OSA), which has been linked to hypertension in the general population, may play role in hypertensive disorders in pregnancy, including preeclampsia-eclampsia. However, little research has been conducted in Asia (no data in Thailand) on the effects of OSA on preeclampsia-eclampsia. We aimed to examine the association between OSA and preeclampsia-eclampsia among Thai pregnant women.

METHODS

We conducted a large prospective cohort study among Thai pregnant women who were in the second trimester of singleton pregnancy. The Berlin Questionnaire was administered to evaluate the risk for OSA. Preeclampsia-eclampsia was diagnosed by standard clinical assessment. Multivariate models were applied in adjustment for confounding factors.

RESULTS

Enrolled were 1345 pregnant women. The overall prevalence of high risk for OSA was 10.1% (95% confidence intervals [CIs] 8.5-11.7), and it was significantly associated with pre-pregnancy body mass index and score on the Perceived Stress Scale. An adjusted odds ratio (OR) for preeclampsia-eclampsia in women with high risk for OSA was 2.72 (95% CI 1.33-5.57).

CONCLUSIONS

Pregnant women with high risk for OSA are at increased risks for preeclampsia-eclampsia compared to those with low risk for OSA. Our results support a role for screening for OSA by BQ during antenatal care.

Reactogenicity and immunogenicity of tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis vaccine (Tdap) in pregnant and nonpregnant women

OBJECTIVE

Tetanus toxoid, reduced diphtheria toxoid, and acellular pertusiss (Tdap) vaccine is recommended during each pregnancy, regardless of prior receipt. Data on reactogenicity and immunogenicity, particularly after repeated Tdap, are limited. We compared local injection-site and systemic reactions and serologic response following Tdap in (1) pregnant and nonpregnant women and (2) pregnant women by self-reported prior Tdap receipt.

STUDY DESIGN

Pregnant women (gestational age 20-34 weeks) and nonpregnant women receiving Tdap were enrolled in this observational study. Injection-site and systemic reactions were assessed for one week post-vaccination. Pertussis toxin, filamentous hemagglutinin, pertactin, fimbriae, tetanus and diphtheria specific IgG antibody titers were determined by standardized enzyme-linked immunosorbent assay at baseline and 28 days post-vaccination. Reactogenicity and serologic responses were compared by pregnancy status, and within pregnant women by self-reported prior Tdap receipt.

RESULTS

374 pregnant and 225 nonpregnant women were vaccinated. Severe local or systemic reactions or "any" fever were uncommon (≤3% for both groups). Moderate/severe injection-site pain was significantly higher in pregnant (17.9%) versus nonpregnant (11.1%) women, but did not prompt a healthcare visit. Proportions of other moderate/severe or any severe reactions were not significantly higher in pregnant compared to nonpregnant women. Moderate/severe (including pain) and severe reactions were not significantly higher in pregnant women receiving repeat versus first-time Tdap. Antibody titers increased from baseline to post-vaccination for all vaccine antigens in pregnant and nonpregnant women; post-vaccination titers against pertussis toxin and filamentous hemagglutinin were significantly higher in nonpregnant versus pregnant women (p < 0.01).

CONCLUSION

Tdap was well-tolerated in pregnant and nonpregnant women. Pregnant women were more likely to report moderate/severe pain at the Tdap injection-site compared with nonpregnant women, but did not necessitate medical visits. Prior Tdap receipt did not increase occurrence of moderate/severe local or systemic reactions in pregnant women. Serologic responses to all vaccine antigens were robust. Clinical Trial Registration@ClinicalTrials.gov. NCT02209623. https://clinicaltrials.gov/ct2/show/NCT02209623.

Modifying maternal sleep position in the third trimester of pregnancy with positional therapy: a randomised pilot trial

OBJECTIVE

To evaluate whether the percentage of time spent supine during sleep in the third trimester of pregnancy could be reduced using a positional therapy device (PrenaBelt) compared with a sham device.

DESIGN

A double-blind, randomised, sham-controlled, cross-over pilot trial.

SETTING

Conducted between March 2016 and January 2017, at a single, tertiary-level centre in Canada.

PARTICIPANTS

23 participants entered the study. 20 participants completed the study. Participants were low-risk, singleton, third-trimester pregnant women aged 18 years and older with body mass index <35 kg/m² at the first antenatal appointment for the index pregnancy and without known fetal abnormalities, pregnancy complications or medical conditions complicating sleep.

INTERVENTIONS

A two-night, polysomnography study in a sleep laboratory. Participants were randomised by computer-generated, one-to-one, simple randomisation to receive either a PrenaBelt or a sham-PrenaBelt on the first night and were crossed over to the alternate device on the second night. Allocation concealment was by unmarked, security-tinted, sealed envelopes. Participants, the recruiter and personnel involved in setting up, conducting, scoring and interpreting the polysomnogram were blinded to allocation.

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary outcome was the percentage of time spent supine during sleep. Secondary outcomes included maternal sleep architecture, respiration, self-reported sleep position and feedback.

RESULTS

The median percentage of sleep time supine was reduced from 16.4% on the sham night to 3.5% on the PrenaBelt night (pseudomedian=5.8, p=0.03). We were unable to demonstrate differences in sleep architecture or respiration. Participants underestimated the time they spent sleeping supine by 7.0%, and six (30%) participants indicated they would make changes to the PrenaBelt. There were no harms in this study.

CONCLUSIONS

This study demonstrates that the percentage of sleep time supine during late pregnancy can be significantly reduced via positional therapy.

TRIAL REGISTRATION NUMBER

NCT02377817; Results.